I wake up my computer from power-save mode by...

Moving the mouse around wildly
Moving the mouse around in a controlled manner
Accidentally bumping my desk, which in turn moves my mouse around wildly
Clicking one of the mouse buttons
Pounding the keyboard
Pressing the shift key
Pressing the spacebar
Pressing another key which I believe will not affect any open programs or windows
Pressing any key, not caring if it affects any open programs or windows